DKIM Deployment

[Dave CROCKER <>]

a receiving sendmail "replaces" the contents of message header fields?  It 
should not do that.

or are you saying that a sending sendmail will replace the contents?  Presumably 
you are saying that this happens after DKIM signing, when it should happen before.

d/

On 4/23/2010 7:04 AM, Jose-Marcio Martins da Cruz wrote:
> Hello,
>
> I've just felt on a problem with CNAMES, not related to DKIM, but which
> can have some implications.
>
> Well, the *default* sendmail configuration has confDONT_EXPAND_CNAMES.
> Brian Costales Bat Book recommends to change the default configuration
> to True, which most people don't, as this isn't the default value.
>
> So, consider a hostname defined as (hopefully, there aren't too many) :
>
> lists-one.domain.com. CNAME lists.domain.com.
> lists.domain.com. A 1.2.3.4
>
> When sendmail receives this, with the default configuration option it
> will replace the contents of headers (To:, CC: and probably others too)
> referencing list-one.domain.com to lists.domain.com.
>
> And this can break DKIM signature.
>
> Did someone other than me already found this ?
>
> Regards
>
> José-Marcio

--

  Dave Crocker
  Brandenburg InternetWorking
  bbiw.net