[Mailman-Developers] dkim-signature headers

[Michael Thomas]

Mark Sapiro wrote:
> Michael Thomas wrote:
> My point is that for what I consider good reasons, Mailman will add the
> msg_footer to such a message by wrapping additional MIME structure
> around the original multipart/alternative message.
>
> I.e., the original
>
> multipart/alternative
>     text/plain
>     text/html
>
> message will be recast as
>
> multipart/mixed
>     multipart/alternative
>         text/plain
>         text/html
>     text/plain
>   

Ah yes, multipart/alternative vs. lists is definitely unhappy for DKIM,
though simpler mime layouts make it through on average -- at least
given our sample. I agree that if you have to add a footer at all, that
the way your doing it in this case seems perfectly reasonable.
> with the final text/plain part containing the footer. Given that the
> original content-type header is included in the signature, the
> signature is now broken.
>
> If we were to take a different approach with a signature containing l=,
> either the l= includes all the text/plain and at least part of the
> text/html, in which we can't add the footer to the text/plain
> alternative without breaking the signature, or the l= includes none of
> the text/html part in which case the signature is not very good at
> verifying the validity of the text/html part. This further assumes we
> even know how to add a footer to a text/html part.
>
>   
Are you still speaking of multipart/alernative? Right now what we do 
for, say,
text/html is not sign the trailing </body></html> and final --. This 
allows lists
to insert their trailers as they normally do in the mime/html body. 
Similar for
text/plain too. For us at least (and it may be that we're just have a 
lot of html hating
geeks), this seems to do the trick pretty well. I see some breakage from 
multipart/
alternative, but not _that_ much.


       Mike