Re: Re: What the verifier can do

Tony Hansen wrote:

> Paul Hoffman wrote:
>  
>
>
> Paul, which hash where? There is no hash in the dkim signature for the
> headers, only a hash for the body and the resulting signature.
>
> Now, *if* there were a header hash in the signature, each of your other
> steps 2-4 would be accurate. But there isn't, which is why the algorithm is:
>
>   1)    calculate the body hash
>   2)    verify the hash of the body
>         2a) if desired, apply heuristics to body and repeat from 1
>   3)    verify the signature using RSA
>         3a) if desired, apply heuristics to headers and repeat from 3
>  
>
> If you're going to apply heuristics to the headers, you can't get away
> from recalculating the RSA signature after each application of the
> heuristics.
>  
I think you're both saying the same thing. The RSA verify operation yields
a hash that you compare against the hash of the headers (and body from bh).
I think that's what Paul is referring to.

      Mike