On 28 Apr 2015 17:04:31 EDT, "John R Levine" <jo...@taugh.com> wrote:
> > 4. Because the Sender Domain signature is valid and contains tf= and stf= > > tags, Recipient validators reconstruct the original message ... > > Oh, it's message wrapping. There are easier ways to do that without > changing DKIM: have the list send the message as a single entry MIME > digest. Mailman already knows how do to that, and in the extremely > implausible event that you can persuade MUAs to do message reconstruction, > it's easy to unwrap using existing tools. I think I've failed to communicate. Yes, the pristine original message will be appropriately MIME-wrapped, with the list decorations becoming separate MIME parts, but the MUA is not expected to do anything except to present the MIME message to the final recipient. The message reconstruction is to be done by the validator at the recipient's end, which will presumably be an MTA because it has the job of accepting or rejecting messages. The only reason for reconstructing the original message is to let DKIM check the validity of the From-aligned signature against the original message. Apart from the addition of tags, there isn't much change for DKIM. What changes is the algorithm used by DMARC in the special case where there exists a From-aligned but invalid signature and a Sender-aligned valid signature specifying the tf= tag and (if there's a consensus) an stf= tag. MJA _______________________________________________ dmarc mailing list dmarc@ietf.org https://www.ietf.org/mailman/listinfo/dmarc
