Re: [spfbis] Document shepherd review of draft-ietf-spfbis-4408bis-14

On Tuesday, April 23, 2013 04:08:39 PM S Moonesamy wrote:
> Hello,
> 
> Here's my review as Document Shepherd.  draft-ietf-spfbis-4408bis is
> nearly ready for publication as a Proposed Standard.  I took into
> consideration the restrictions in the SPFBIS Charter and the
> controversial working group discussions in making this assessment.
> 
> In the Abstract:
> 
>    "This document describes version 1 of the Sender Policy Framework
>     (SPF) protocol, whereby an ADMD can explicitly authorize the hosts
>     that are allowed to use its domain names, and a receiving host can
>     check such authorization."
> 
> ADMD should be expanded in the above.  This was pointed out in a
> review posted on August 26, 2012 [1].

Fixed.

> In Section 2.1:
> 
>    'It is RECOMMENDED that SPF verifiers not only check the "MAIL FROM"
>     identity, but also separately check the "HELO" identity by applying
>     the check_host() function (Section 4) to the "HELO" identity as the
>     <sender>.'
> 
> As a note this "RECOMMENDED" is also in RFC 4408.
> 
>     'Note that requirements for the domain presented in the EHLO or HELO
>      command are not always clear to the sending party, and SPF verifiers
>      MUST be prepared for the "HELO" identity to be malformed or an IP
>      address literal.'
> 
> This RFC 2119 "MUST" is not in RFC 4408.  It is a substantive change
> in my opinion.

Fixed.

>    "This SPF check can only be performed when the "HELO" string is a
>     valid fully qualified domain."
> 
> What is a valid fully qualified domain?

Would s/domain/domain name/ clear it up for you?

> In Section 2.2:
> 
>    'SPF verifiers MUST check the ""MAIL FROM" identity if a completed
>     "HELO" check has not reached a definitive policy result by applying
>     the check_host() function to the "MAIL FROM" identity as the
>     <sender>.'
> 
> As a note this RFC 2119 MUST is already in RFC 4408.
> 
> In Section 2.3:
> 
>    "An SPF-compliant domain MUST have valid SPF records as described in
>     Section 3."
> 
> As a note the RFC 4408 text is:
> 
>    "An SPF-compliant domain MUST publish a valid SPF record as described
>     in Section 3."
> 
> The RFC 2119 MUST is redundant.

Is there a reason to change it?

>    'If domain owners choose to publish SPF records and want to support
>     receivers making negative authorization determinations, then they MUST
>     publish records that end in "-all", or redirect to other records that
> do, otherwise, no definitive determination of authorization can be made.'
> 
> The document uses ADMD while there is "domain owners" in the
> above.  I suggest reviewing that.

Changed

> The RFC 2119 MUST is a substantive change.  Why is this a MUST?

Because it's the literal truth.  That's what you have to do to achieve that 
result.  You won't interoperate with receivers in that way effectively if you 
don't.

> In Section 2.4:
> 
>    'At least the "MAIL FROM" identity MUST be checked, but it
>     is RECOMMENDED that the "HELO" identity also be checked beforehand.'
> 
> There is already a RFC 2119 MUST in Section 2.2.  There is also a RFC
> 2119 RECOMMENDED in Section 2.1.  The above text restates existing
> RFC 2119 requirements or recommendations.

Modified to make them non-redundant.

>    'Without explicit approval of the domain owner, checking other
>     identities against SPF version 1 records is NOT RECOMMENDED because
>     there are cases that are known to give incorrect results.'
> 
> How should this explicit approval be sought?  This recommendation
> does not make sense.

What I have now is "Documents that define other identities will have to define 
the method for explicit approval."

> In Section 2.4:
> 
>    'When a mail receiver decides to perform an SPF check, it MUST use a
>     correctly-implemented check_host() function (Section 4) evaluated
>     with the correct parameters.'
> 
> This RFC 2119 requirement states the obvious.  It basically says that
> there is a requirement in draft-ietf-spfbis-4408bis-14 to use a
> correct implementation of draft-ietf-spfbis-4408bis-14.

This was changed already due to other comments.  I think it makes sense now.  
Please check when -15 is published.

>    'Although invalid, malformed, or non-existent domains cause SPF checks
>     to return "none" because no SPF record can be found, it has long been
>     the policy of many MTAs to reject email from such domains, especially
>     in the case of invalid "MAIL FROM".  Rejecting email will prevent one
>     method of circumventing of SPF records.'
> 
> This text is already in RFC 4408.
> 
>    "Implementations have to take care to correctly extract the <domain>
>     from the data given with the SMTP MAIL FROM command as many MTAs will
>     still accept such things as source routes ..."
> 
> The definition of <domain> is:
> 
>    'the domain portion of the "MAIL FROM" or "HELO" identity.'
> 
> I am not sure whether it is even a definition.  From an
> implementation perspective the last paragraph of Section 2.4 is unclear.

It seems clear to me.  Could you expand on why you think it's problematic or 
provide recommended text.

> In Section 2.5:
> 
>    "The authorization check SHOULD be performed during the processing of
>     the SMTP transaction that sends the mail."
> 
> This RFC 2119 SHOULD is already in RFC 4408.
> 
>    'Performing the authorization other than using the return-path and
>     client address at the time of the MAIL command during the SMTP
>     transaction can cause problems, ..'
> 
> Shouldn't that be "authorization check"?

Yes.  Fixed.

>    'Generating non-delivery notifications to forged identities that have
>     failed the authorization check is a source of backscatter and SHOULD
>     be avoided.'
> 
> This RFC 2119 SHOULD is not in RFC 4408.  The above does not have
> anything to do with Sender Policy Framework.  It was mentioned during
> WG discussions that "SPF can help the backscatter problem" [2].  This
> text may have been introduced in response to a review [3].  Is this
> an enhancement or a clarification?

It's a clarification.

> In Section 2.6:
> 
>    "An SPF verifier implements something semantically identical to the
>     function defined there."
> 
> John Levine commented about this during the WGLC [4].  I am listing
> this as a reminder for myself.
> 
> In Section 2.6.1:
> 
>    'A result of "none" means either (a) no syntactically valid DNS domain
>     name was extracted from the SMTP session that could be used as the
>     one to be authorized, or (b) no TXT records were retrieved from the
>     DNS that appeared to be intended for use by SPF verifiers.'
> 
> I suggest "DNS TXT records".  What is a syntactically valid DNS
> domain name?  The definition of "none" in RFC 4408 is clear (to me).

How could one retrieve anything other than DNS TXT records from the DNS?  That 
seems redundant since it says "retrieved from the DNS".

> In Section 2.6.2:
> 
>    'The domain owner has explicitly stated that it is not asserting
>     whether the IP address is authorized.  This result MUST be treated
>     exactly like the "none" result; the distinction exists only for
>     informational purposes.'
> 
> As a note, the RFC 2119 MUST is in RFC 4408.  The Introduction
> Section mentions "ADMDs can authorize hosts to use their domain
> names".  The above uses "domain owner".

Changed to ADMD.  Made the same change in 2.6.5 as well.

> In Section 2.6.7:
> 
>    'A "permerror" result means the domain's published records could not
>     be correctly interpreted.  This signals an error condition that
>     definitely requires manual intervention to be resolved.'
> 
> What is "manual intervention" in the above?

Would operator intervention or operator action be better?

> In Section 3:
> 
>    'An SPF record is a DNS record that declares which hosts are, and are
>     not, authorized to use a domain name for the "HELO" and "MAIL FROM"
>     identities.'
> 
> How are hosts which are not authorized to use a domain name listed in
> a SPF record?

If a record contains something like -a:host.example.com that host is 
explicitly not authorized.

>    "The SPF record is a single string of text."
> 
> What is a single string of text?  It may be easier to state this in
> terms of record format.

I think this was addressed in a later comment and it should be improved.

>    'ADMDs publishing SPF records SHOULD try to keep the number of
>     "include" mechanisms and chained "redirect" modifiers to a minimum.'
> 
> What is the minimum?  Note that this RFC 2119 SHOULD is in RFC 4408.

It's the least an ADMD needs to properly describe the hosts authorized to send 
mail from their domain.  It's minimum in the sense of no more than needed.

>    'ADMDs SHOULD also try to minimize the amount of other DNS information
>     needed to evaluate a record.'
> 
> This RFC 2119 SHOULD is also in RFC 4408.  There are two RFC 2119
> SHOULDs in the last paragraph of Section 3.  This usage of RFC 2119
> key words does not help the SPF "publisher".   In my opinion the
> "SHOULD try" in this context uses the RFC 2119 key word in unorthodox ways.

I took try out of the section.  I think that should do it.

> In Section 3.1:
> 
>    'SPF records MUST be published as a DNS TXT (type 16) Resource Record
>     (RR) [RFC1035] only.'
> 
> I would ask why "MUST be published ... only".  By the way, Section 3
> has a reference to Section 4 for record format instead of Section
> 3.1.  Is that correct?

The only is to make it clear that the Type SPF records that were defined in RFC 
4408 are no longer part of the protocol.  It is correct.  The ABNF for the 
record format is in section 4.

> In Section 3.2:
> 
>    "A domain name MUST NOT have multiple records that would cause an
>     authorization check to select more than one record."
> 
> This RFC 2119 MUST NOT was in RFC 4408.  Is this to help the SPF
> "publisher" and if so, how does it help?

4408 has an implicit requirement for this.  In section 4.5, it says:

> If the resultant record set includes more than one record, check_host()
> produces the "permerror" result.

The MUST NOT here makes it clear the condition has to be avoided.   It's not a 
functional change in the protocol.

> In Section 3.3:
> 
>    "As defined in [RFC1035] sections 3.3.14 and 3.3, a single text DNS
>     record can be composed of more than one string."
> 
> See previous comment about " a single string".
> 
>    "If a published record contains multiple character-strings, then the
>     record MUST be treated as if those strings are concatenated together
>     without adding spaces."
> 
> This RFC 2119 MUST is also in RFC 4408.  I suggest removing the
> "MUST" in the example.

Why?  If you don't do it that way, the result is not interoperable.

>    "TXT records containing multiple strings are useful in constructing
>     records that would exceed the 255-byte maximum length of a character-
>     string within a single TXT record."
> 
> I suggest using "octet" instead of "byte".  I'll point the working
> group to CVE-2008-2469 in case it might wish to consider that issue.

The CVE is unrelated.

> In Section 4:
> 
>    "A compliant SPF implementation MUST do something semantically equivalent
> to this description."
> 
> It's unusual to see a "do something" RFC 2119 requirement in a
> specification.  Is the SPFBIS WG working on compliance for SPF
> implementations?

It was added as part of making check_host() not a formal API/functional 
specification.  You need an equivalent result, but needn't follow all the steps 
exactly.  Please recommend an alternative.

>    "Mail receivers that perform this check MUST correctly evaluate the
>     check_host() function as described here."
> 
> Where does "mail receivers" fit in the Sender Policy Framework?  The
> "MUST correctly evaluate" is stating the obvious.

Receiving ADMDs.  Fixed.

>    "Implementations MAY use a different algorithm than the canonical
>     algorithm defined here, so long as the results are the same in all
>     cases."
> 
> Why is this a RFC 2119 MAY?  I am aware that the text is in RFC 4408.

trying to make it clear there's flexibility for the implementer.  Do you think 
it should be changed?

> In Section 4.1:
> 
>    '<domain> - the domain that provides the sought-after authorization
>                information; initially, the domain portion of the "MAIL
>                FROM" or "HELO" identity.'
> 
> The above text is different from the text in Section 2.4.

Yes, but not inconsistent with it.

> In Section 4.3:
> 
>    "If the <domain> is malformed (e.g. label longer than 63 characters,
>     zero-length label not at the end, etc.)"
> 
>   That should be "octets".

I recall further discussion about this in a later message in the thread.  I'll 
address it there.

>    "Properly formed domains are fully qualified email domains as
>     described in [RFC5321] Section 2.3.5."
> 
> What are "properly qualified email domains"?

What it says they are in the reference.

>    "Internationalized domain names MUST be encoded as A-labels, as
>    described in Section 2.3 of [RFC5890].on 2.3 of [RFC5890]."
> 
> I'm listing the above and leave it to Area Director guidance.  Please
> note that it is a new RFC 2119 requirement.

It's a new requirement because IDN wasn't addressed in 4408.  It's necessary 
to address it now and the WG agreed this was the best way to do it.

> In Section 4.4:
> 
>    "In accordance with how the records are published (see Section 3
>     above), a DNS query needs to be made for the <domain> name, querying
>     for type TXT only."
> 
> I don't understand the sentence.

What don't you understand?

>    'Alternatively, for a server failure (RCODE 2) result, check_host()
>     MAY track failures and treat multiple failures within 24 hours for
>     the same domain as "permerror".'
> 
> This text is not in RFC 4408.  I found a note in Issue #1 [5] and in
> a message [6].

Yes.  This is a change to address an operational issue found during SPF 
deployment.

> In Section 4.6.2:
> 
>    "If there are no more mechanisms, the result is specified in
>     Section 4.7."
> 
> This sentence does not make sense.

If I changed it to "If there are no more mechanisms, the result is the default 
result as described in section 4.7" would it be clearer?
> 
> In Section 4.6.4:
> 
>    "SPF implementations MUST limit the total number of mechanisms and
>     modifiers ("terms") that cause any DNS query to at most 10 during SPF
>     evaluation."
> 
> This was discussed on the mailing list [7].
> 
>    "If this number is exceeded during a check, a permerror MUST be
> returned."
> 
> I read this as if an implementation-specific limit is reached a
> permerror is returned.  There are two RFC 2119 MUST in the
> above.  That can be reduced to one MUST.

Is there a problem with it the way it is?

> I read the first paragraph of Section 4.6.4.  I am not sure how the
> absolute requirement will be interpreted by the reader.

We worked on making it clearer.  If you have suggested improvements, please 
send them.

>    'MTAs or other processors SHOULD impose a limit on the maximum amount
>     of elapsed time to evaluate check_host().  Such a limit SHOULD allow
>     at least 20 seconds.  If such a limit is exceeded, the result of
>     authorization SHOULD be "temperror".'
> 
> There are three RFC 2119 SHOULDs in the above.  I suggest rewriting
> the text to reduce that.

They are three different things.  Why would rewriting it help?

>    'SPF implementations SHOULD limit "void lookups" to two.'
> 
> What are void lookups?

The term is defined in the two immediately preceding sentences.

>    "In this case, a default of two is RECOMMENDED."
> 
> Why is "two" recommended?

Because that's the limit that is currently widely deployed (in the perl 
Mail::SPF implementation) with which there has been good experience.

>    'Note that records SHOULD always use either a "redirect" modifier or
>     an "all" mechanism to explicitly terminate processing.'
> 
> Why is there a RFC 2119 key word in a note?

Took out the 2119 word.

> In Section 4.8:
> 
>    'e.g., "foo..example.com") or overlong labels (more than 63
>     characters).'
> 
> I suggest octets.
> 
> in Section 5:
> 
>    'SPF implementations on IPv6 servers need to handle both "AAAA" and "A"
>     secords, for clients on IPv4 mapped IPv6 addresses [RFC4291].'
> 
> There is a typo, "records".

Already fixed.

> I'll flag the above for review by people with IPv6 expertise.

What's in -15 is the result of the review and WG feedback.

> In Section 5.3:
> 
>    'a   = "a"      [ ":" domain-spec ] [ dual-cidr-length ]'
> 
> "dual-cidr-length" is introduced in this sub-section.  I had to
> search through the draft to find out what it means.
> 
> In Section 5.4:
> 
>    'Note regarding implicit MXs: If the <target-name> has no MX records,
>     check_host() MUST NOT pretend the target is its single MX, and MUST
>     NOT default to an A or AAAA lookup on the <target-name> directly.'
> 
> There are two RFC 2119 MUSTs in the above.  This is over-usage of RFC
> 2119 key words.  This text was in RFC 4408.  This is not a divergence
> from RFC 5321, it is a contrary to Section 5 of RFC 5321.

It's not contrary.  It's saying that aspect of 5321 is not relevant to SPF.  
In any case, changing it would be a substantiative change to the protocol that 
would require all implementations to be updated.

> In Section 5.5:
> 
>   "This mechanism SHOULD NOT be used."
> 
> I suggest providing a reason for this.

The reason is given in the note at the end of the section.

>    "To prevent DoS attacks, more than 10 PTR names
>     MUST NOT be looked up during the evaluation of a "ptr" mechanism
>     (see Section 4.6.4)."
> 
> The above restates a previous RFC 2119 MUST.
> 
>    "If used, proper PTR records MUST be in place for the domain's hosts
>     and the "ptr" mechanism SHOULD be one of the last mechanisms checked."
> 
> Those RFC 2119 key words are not in RFC 4408.  I don't see how this
> RFC 2119 change qualifies as a clarification or explanation.

For the MUST, it flat out won't work if you don't have those (no 
interoperation).  For the SHOULD, it's an optimization.  We can change it if 
you want.

>    "It is, however, still in use and part of the SPF protocol, so compliant
>    check_host() implementations MUST support it."
> 
> What is a compliant check_host() implementation?

One that works in accordance with 4408bis.  Please suggest an alternative if 
you don't like that.

> In Section 5.6:
> 
>    "ip6-network      = <as per [RFC 4291], section 2.2>"
> 
> I suggest that the above reference be verified for correctness.
> 
> In Section 5.7:
> 
>    'v=spf1 exists:%{ir}.%{l1r+-}._spf.%{d} -all'
> 
> I'll flag this for review by DNS folks.
> 
> In Section 6:
> 
>    'The modifiers defined in this document ("redirect" and "exp") MAY
>     appear anywhere in the record, but SHOULD appear at the end, after
>     all mechanisms.'
> 
> This text is in RFC 4408.  I would label the RFC 2119 usage as defective.

Why?

> In Section 6.2:
> 
>    "Since the explanation string is intended for an SMTP response and
>     [RFC5321] Section 2.4 says that responses are in [US-ASCII], the
>     explanation string MUST be limited to US-ASCII.'
> 
> It would be easier to defer to RFC 5321 instead of setting a RFC 2119
> requirement in this draft.  I note that this requirement was not in RFC
> 4408.

It's not a new requirement.  If you couldn't find it in 4408, then that means 
we've succeeded in making the actual requirement more clear.

>    "Software SHOULD make it clear that the explanation string
>     comes from a third party."
> 
> I could not understand what that means in RFC 2119 terms.  The draft
> uses RFC 2119 key words by example instead of providing an explanation.

I don't understand the comment.

> In Section 7.1:
> 
>    'The "toplabel" construction is subject to the LDH rule plus
>     additional top-level domain (TLD) restrictions.'
> 
> Where can I find these restrictions?  Please note that I have read
> the Informational RFC.

LDH + non-numeric as the RFC says.

> In Section 7.3:
> 
>    "-exists:%(ir).sbl.spamhaus.example.org"
> 
> I commented about vendor-neutral previously [8].  The above is a way
> to get around the objection [9].  I suggest cleaning this up.

Took spamhaus out.

>   "so trailing dots SHOULD NOT be published by domain owners"
> 
> Why is it "domain owners"?

Took out everything after published.

>    "This macro SHOULD NOT be used.  See Section 5.5 for the discussion
>     about why not."
> 
> This comes out as a flippant explanation for the RFC 2119 SHOULD.

Please recommend non-flippant text then.  It doesn't read that way to me.

>    "This SHOULD be a fully qualified domain name, but if one does not
>     exist (as when the checking is done by a MUA) or if policy restrictions
>     dictate otherwise, the word "unknown" SHOULD be substituted."
> 
> The RFC 2119 key words are in RFC 2119.  I don't know what to say.

OK.

>    "When the result of macro expansion is used in a domain name query, if
>     the expanded domain name exceeds 253 characters (the maximum length
>     of a domain name), the left side is truncated to fit, by removing
>     successive domain labels (and their following dots) until the total
>     length does not exceed 253 characters."
> 
> Where is it specified that the maximum length of a domain name is 253
> characters?

This was covered in someone else's response.

>    "Care has to be taken by the sending ADMD so that macro expansion for
>     legitimate email does not exceed the 63-character limit on DNS labels."
> 
> Where is that 63-character limit specified?

This was covered in someone else's response.

> It is odd to have RFC 2119 requirements under a "Notes" heading.

They aren't really notes in that sense.  If you have a better name for the 
section, please suggest.

> In Section 8.2:
> 
>    'A "neutral" result MUST be treated exactly like the "none" result;
>     the distinction exists only for informational purposes.'
> 
> Why is an existing RFC 2119 restated?

Because of the structure of the document that the WG came up with.  I don't 
find a good way to avoid it and not make it less readable.

> In Section 8.5:
> 
>    "The domain owner believes the host is not authorized but is not willing
>     to make a strong policy statement."
> 
> Why is it domain owner?

 Because conversion to the newer terms was incomplete.  I clean up this and 
some others as well.

> In Section 9:
> 
>    "An operator could choose to use both to serve different downstream
>     agents.  In such cases, care needs to be taken to ensure both fields
>     are conveying the same details, or unexpected results can occur."
> 
> This has been discussed on the mailing list.  I don't think that it
> encourages interoperability but the working group decided otherwise [10].
> 
> In Section 9.1:
> 
>    "The Received-SPF header field is a trace field (see [RFC5322] Section
>     3.6.7) and SHOULD be prepended to the existing header, above the
>     Received: field that is generated by the SMTP receiver."
> 
> "prepended to the existing header" does not sound right.

I believe it is.

>    "It MUST appear above all other Received-SPF fields in the message."
> 
> How does this fit into the previous RFC 2119 SHOULD?

It will generally happen as a natural result of following the previous one, 
but is there in case more than one is added by a single MTA.

> in Section 10:
> 
>    "This section is not a "how-to" manual, or a "best practices" document,
>     and it is not a comprehensive list of what such entities SHOULD do in
>     light of this document."
> 
> What is the meaning of the RFC 2119 SHOULD in the above?

Got rid of it.
> 
> In Section 10.1.1:
> 
> There was a comment from Authur Thisell about the table [11] in this
> sub-section.

There didn't seem to be support for changing it though.

> In Section 10.1.2:
> 
>    "Publishing SPF records for domains that send no mail is
>     a well established best practice."
> 
> I am not aware of that best practice.  I did a few DNS queries:
> 
> ;; QUESTION SECTION:
> ;bing.com.                      IN      TXT
> 
> ;; ANSWER SECTION:
> bing.com.               3600    IN      TXT     "v=msv1
> t=6097A7EA-53F7-4028-BA76-6869CB284C54"
> 
> ;; QUESTION SECTION:
> ;com.com.                       IN      TXT
> 
> ;; ANSWER SECTION:
> com.com.                293     IN      TXT
> "google-site-verification:esSnoZdChIkkfCfS9MMgqNhE0yaXfnnZWdZPuBf7e8k"

OK.  See 
http://www.bits.org/publications/security/BITSEmailAuthenticationFeb2013.pdf

> In Section 10.1.3:
> 
>    "SPF functionality is enhanced by administrators ensuring this
>    identity is set correctly and has an appropriate SPF record."
> 
> How is SPF functionality enhanced?

If there's an SPF record for HELO as well as Mail From, then a check can be 
performed on bounces.

> In Section 10.2:
> 
>    "As stated elsewhere in this document, there is no normative requirement
>     for specific handling of a message based on any SPF result."
> 
> The "as stated elsewhere" is vague.

It comes up multiple places.  Adding several specific reference won't improve 
the draft.

>    'The primary considerations are that SPF might return "pass" for mail
>     that is ultimately harmful (e.g., spammers that arrange for SPF to
>     pass using nonsense domain names'
> 
> What are "nonsense" domain names?

There was follow-on discussion about this.

> In Section 10.3:
> 
>    "The mediator can make the newly-posted message be as similar or as
>     different from the original message as they wish."
> 
> The sentence seems incomplete, i.e. similar to what.

The original message.

>    "For the operation of SPF, the essential concern is the email
>     address in the 5321.MailFrom command for the new message."
> 
> What does this mean?

It means that's the thing that's the most important.

>    'Because SPF evaluation is based on the IP Address of the "last"
>     sending SMTP server, the address of the mediator will be used, rather
>     than the address of the SMTP server that sent the message to the
>     mediator.'
> 
> I'll note that this is a mix of RFC 5321 and RFC 5598.  The result is
> clear or unclear depending on the background of the reader.

I guess I have the background for it to be clear.  Please suggest an 
improvement.

> In Section 11.5:
> 
>    "An SPF compliant receiver gathers information from the SMTP commands
>     it receives and from the published DNS records of the sending domain
>     holder"
> 
> I suggest explaining the untrusted part.

That's what the section does.

> In Section 11.6:
> 
>    "Checking SPF records causes DNS queries to be sent to the domain
>     owner."
> 
> How are DNS queries sent to domain owners?

Fixed it.

> Section 12:
> 
> I note that Murray S. Kucherawy has contributed significantly to
> draft-ietf-spfbis-4408bis.  If I am not mistaken it is IETF practice
> to acknowledge such contributions.  I don't recall who sent text at
> the moment.  If you did, please send an (off-list) email to the
> SPFBIS WG Chairs.

There are many, many people who contributed to both 4408 and 4408bis that 
aren't listed.  If someone wants to make a list of people who made a 
significant contribution, I'll be glad to include it.

> In Section 13.1:
> 
>    "The format of this type is identical to the TXT RR [RFC1035]"
> 
> The format is not identical, i.e. it's a different RR.  I suggest
> keeping the IANA Considerations Section simple, i.e. clearly explain
> to IANA what action is requested.

Yes, it is.

> In Section 13.2:
> 
>    "Per [RFC3864], the "Received-SPF:" header field is added to the IANA
>     Permanent Message Header Field Registry."
> 
> Note to self: request removal from the provisional message  header
> field registry.
> 
> The "status:" should be "standard"

Not Standards Track?

> In Section 13.3:
> 
>    "Their status should not be changed."
> 
> I suggest "Their status is unchanged".  BTW, it should be "SPF
> Modifier Registry".

Fixed

> I suggest following RFC 6652 Section 5.1.

> An "Updates:" for RFC 6652 may be needed.

Why?  It's the registry that gets updated, not 6552.
> 
> References:
> 
> Why is RFC 1123 a normative reference?

See section 2.4.
> 
> Why is RFC 3864 a normative reference?

Because it defines how the Received-SPF registration is done.
> 
> Where can I find "Designated Mailers Protocol"?

See draft-fecyk-dsprotocol
> 
> Where can I find "Domain-Authorized SMTP Mail"?

I don't have a copy of this.

> ABNF:
> 
> Did anyone verify the ABNF?
> 
> In Appendix C:
> 
> In Section E.1:
> 
>    'This would cause a lookup on an DNS white list (DNSWL) and cause a
>     result of "fail" only for email not either coming from the
>     domain's mx host(s) (SPF pass) or white listed sources (SPF
>     neutral).'
> 
> I didn't find any discussion about this on the SPFBIS mailing
> list.  is there an explanation for this change between RFC 4408 and this
> draft?

It was pointed out that this is a white list, not a black list.

> I note that there are 48 pages in RFC 4408.  There are 78 pages in
> this draft.  A significant amount of text has been added in the
> Appendix (over 20 pages).  I doubt that the text has been carefully
> reviewed.  I may be asked for an explanation about all that once the
> draft leaves this working group.

Why wait?

> In Appendix I:
> 
> Appendix I is about "Protocol Status".  This draft is intended as a
> Proposed Standard. From an IETF perspective that is what it will
> be.  Describing it as something different can be misleading.
> 
>    "[RFC4408] was designed to clearly document the protocol defined by
>     earlier draft specifications of SPF as used in existing
>     implementations.  This updated specification is intended to clarify
>     identified ambiguities in [RFC4408], resolve techincal issues
>     identified in post-RFC 4408 deplyment experience, and document widely
>     deployed extensions to SPF that have been developed since [RFC4408]
>     was published."
> 
> Extensions to the SPF protocol are clearly mentioned in the charter
> as being out of scope.  The "document widely deployed extensions" is
> problematic.

The charter specifically allows for "addition of any enhancements 
that have already gained widespread support".

>    "This document updates and replaces RFC 4408 that was part of a group
>     of simultaneously published Experimental RFCs (RFC 4405, RFC 4406,
>     RFC 4407, and RFC 4408) in 2006.  At that time the IESG requested the
>     community observe the success or failure of the two approaches
>     documented in these RFCs during the two years following publication,
>     in order that a community consensus could be reached in the future."
> 
> Why is this needed?  The SPFBIS WG produced RFC 6686 to resolve the
> experiment.

Since this is what obsoletes 4408, not everyone will read 6686.

>    "SPF is widely deployed by large and small email providers alike.
>     There are multiple, interoperable implementations."
> 
> Someone might point out that this is marketing instead of text
> relevant to a protocol.  I'll mention that one or more significant
> issues (e.g. Issue #9) was identified during the WG
> discussions.  Issue #9 was not listed as the errata.  I suggest
> removing the section as it will be less text and there is already two
> informative references to help the reader find background information.

#9 has been known since before 4408 was published.  In 2005 it was the price 
of admission to the IETF.

> Regards,
> S. Moonesamy (as document shepherd)
> 
> 1. http://www.ietf.org/mail-archive/web/spfbis/current/msg02371.html
> 2. http://www.ietf.org/mail-archive/web/spfbis/current/msg00928.html
> 3. http://www.ietf.org/mail-archive/web/spfbis/current/msg01810.html
> 4. http://www.ietf.org/mail-archive/web/spfbis/current/msg03378.html
> 5. http://trac.tools.ietf.org/wg/spfbis/trac/ticket/1
> 6. http://www.ietf.org/mail-archive/web/spfbis/current/msg00630.html
> 7. http://www.ietf.org/mail-archive/web/spfbis/current/msg00199.html
> 8. http://www.ietf.org/mail-archive/web/spfbis/current/msg02279.html
> 9. http://www.ietf.org/mail-archive/web/spfbis/current/msg02308.html
> 10. http://www.ietf.org/mail-archive/web/spfbis/current/msg02526.html
> 11. http://www.ietf.org/mail-archive/web/spfbis/current/msg02763.html
> 
> _______________________________________________
> spfbis mailing list
> spfbis@ietf.org
> https://www.ietf.org/mailman/listinfo/spfbis