ietf-dkim
[Top] [All Lists]

Re: [ietf-dkim] Output requirements

2011-05-09 04:34:09
On Sat, 07 May 2011 13:50:41 +0100, Alessandro Vesely 
<vesely(_at_)tana(_dot_)it>  
wrote:

On 06/May/11 20:37, Murray S. Kucherawy wrote:
   Verifiers SHOULD ignore those signatures that produce a PERMFAIL
   result (see Section 7.1), acting as though they were not present
   in the message.  ...

s/Verifiers SHOULD ignore/Identity assessors SHOULD ignore/

(and probably in other places too). Verifiers are explicitly  
instructed
to return PERMFAIL/TEMPFAIL), and "returning" something is evidently
inconsistent with "ignoring" it.

+1

Since this is already somewhat mushy, might I suggest:

Verifiers MAY decline to report, and identity assessors SHOULD ignore,  
...

I wouldn't delve into what identity assessors should do, since that is
outside the scope of the DKIM Signing specification.  The wording in
section 3.9 already conveys that "ignoring" is being used as a synonym
for "returning PERMFAIL".  I'd make such meaning more explicit rather
than introducing yet a new phrase to allude to the same behavior.

Yes, the wording certainly needs clarifying.

Essentially, a Verifier is a module within a server that is called upon to  
express an opinion regarding the vailidity of the signature(s) in some  
message.

As such, it is bound to return SOME result (otherwise the server is just  
going to hang). So phrases like "ignore" have no place within it (unles  
INGNORED is a specific permitted response).

Oddly, the present document does not provide a return option PASS (maybe  
that is implicit, but its absence may be the cause of the confusion). It  
does provide PERMFAIL and TEMPFAIL. It also REQUIRES that the 'd=' tag be  
returned (is that only in the PASS case?), and other tags etc. MAY be  
returned (such as the things Hector wants included). But since the message  
itself is still available for inspection, these other returns might be  
regarded as redundant (so long as the particular signature being reported  
on is identifiable when there are several).

If there s no signature at all, does that mean the verifier is never  
called? For sure, if it is called and there is no signature, PERMFAIL is  
to be returned.

But, one way or another, the wording needs cleaning up, and maybe  
explicitly replacing "ignore" by PERMFAIL is enough.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131                       
   Web: http://www.cs.man.ac.uk/~chl
Email: chl(_at_)clerew(_dot_)man(_dot_)ac(_dot_)uk      Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K.
PGP: 2C15F1A9      Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5
_______________________________________________
NOTE WELL: This list operates according to 
http://mipassoc.org/dkim/ietf-list-rules.html

<Prev in Thread] Current Thread [Next in Thread>