On 10/18/10 12:18 PM, Murray S. Kucherawy wrote: > >> This is no more presumptuous than expecting that MUAs will adapt > >> to consume the output of DKIM as it stands now. > > In another message I indicated that I don't presume either, but > assert that there's no middle ground; they will or they won't. If > they will, informative text is sufficient; if they won't, then we > have to start hardening MTAs to defend against MUA attacks because > that's where header changes and other enforcements are possible > since, by definition, any current annotations are invisible and will > stay that way. > > I'm fine with accepting either model, but we have to understand the > implications of picking one. The latter, in particular, involves > some major scope creep.
Should the charter of a security related protocol need to anticipate minor modifications to a verification process, that appears essential for ensuring a DKIM signature is not inappropriately associated with an incorrect From header field? Rather than expecting changes to a plethora of consumers of DKIM results, which might be used for sorting or display, ensuring PERMFAIL occurs whenever replicate From header fields are detected ensures DKIM will not be complicit in deceiving consumers of its results. Adding such a check represents a normative change to DKIM, since it can not be just advisory warnings to DKIM's consumers that suggests when DKIM results should be ignored. -Doug _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html