[ietf-dkim] Re: signature construct

[Dave Crocker]

>
>> Exactly.  You are trying to have DKIM provide a range of information,...
>
> As Earl has pointed out, one thing it lets you do is
> validate the public key signature first, and if it doesn't validate 
> you don't
> need to bother performing the hash operation. (The public key 
> operation is
since the pk computation is usually considered more expensive than the 
hashing, i'm not sure what the benefit is, here, but for a very large 
message, i guess saving the overhead of the hash would be nice.  not a 
point worth serious contortions, but as noted this ain't an expensive 
enhancement. 

I was arguing against subtle semantics, not extra storage.

in any event:
>  And I previously pointed out that this helps tremendously in tracking
> down problems. (And if you don't think this matters, all I can say is you
> haven't written or supported enough implementations of this sort of 
> stuff.)

yeah, like i'm every going to argue against your assessment of 
implementation or performance issues... 

anyhow, it always pisses me off to have my main line of argument become 
irrelevant by virtue of a simple, direct and compelling alternate 
argument.  i probably won't always concede to debugging benefits, but 
pretty close...

so my reaction to your posting along those lines was something like 
game, set, match.


d/