Re: [ietf-822] one can re-sign without a permission to re-sign header

[Brandon Long <[e-mail]>]

On Mon, May 5, 2014 at 1:50 AM, Paul Smith <[e-mail]> wrote:

> On 02/05/2014 15:42, John R Levine wrote:
>
>> I don't see any replay protection in here at all. Nothing that says to
>>> keep the signature expiration relatively short, and nothing which a mailing
>>> list recipient could not subsequently use to send spam. The first issue
>>> just needs a mention. It's the second issue that needs to be addressed IMO:
>>>
>>
>> Yeah, that occurred to me about five minutes after I posted it. Here's a
>> tweaked version where the mf tag is now mf=list.domain, with handwaving
>> about how a may-forward signature doesn't count unless there's also a
>> signature from the list domain.  Given lengthy discussions about how little
>> abuse comes from real mailing lists, that'd probably be adequate.
>>
>> http://datatracker.ietf.org/doc/draft-levine-may-forward/
>>
> Could this be 'extended' to include message-ids in the MF signature?
>
> That would provide some replay protection, especially if the forwarder
> checks for duplicate message-ids (the recipient could also check for
> dupes). Without it, I could see one of your messages on a list, then send
> messages to everyone on the list, pretending to be you.


I was wondering if we wanted a new canonicalization which would allow for
the Subject to be included but stripped of "standard" MLM subject prefixes,
ie something similar to the reply_regexp in mutt (
http://www.mutt.org/doc/devel/manual.html#reply-regexp)

Brandon