Last Call Review of draft-ietf-spfbis-4408bis-19
review-ietf-spfbis-4408bis-19-secdir-lc-hallam-baker-2013-09-12-00

I have reviewed this document as part of the security directorate's

ongoing effort to review all IETF documents being processed by the

IESG.  Document editors and WG chairs should treat these comments just

like any other last call comments.

The document has been produced as part of a proposal to upgrade SPF to
standards track recognizing the state of deployment experience.

Minor issues.

1.1.3

.  MAIL FROM Definition

I found this section completely opaque and very confusing. It should not be
necessary to hunt through other specs to find a definition. Particularly since
the referenced specs do not give an explicit definition for the term as used
and the references point to the whole spec rather than a particular section.

The Security Considerations section is adequate for the purpose except that no
mention is made anywhere in the specification about DKIM and how a mail
receiver should interpret presence of DKIM and SPF policy at the same time.
This is a legitimate concern since DKIM is already a standards track proposal
and SPF is only now being promoted to Standards Track. Thus the SPF document
should address the question of dual use.

8.7

.  Permerror

"

This signals an error condition that

   definitely requires operator intervention to be resolved."

I cannot imagine a circumstance which definitely requires a human to be
involved in mail delivery.

11.2

.  SPF-Authorized Email May Contain Other False Identities

   Do not construe the "MAIL FROM" and "HELO" identity authorizations to
   provide more assurance than they do.

Document has quasi normative language that should be worded as statements of
fact rather than as direction.

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